Allylic alcohols are highly important compounds which are used in a variety of processes. They can be obtained from α,β-unsaturated carbonyl compounds via stoichiometric or catalytic reductions. Catalytic transfer hydrogenation is a safe and convenient method to use for this purpose since it circumvents the use of hydrogen gas or stoichiometric amounts of hydride-containing reducing agents. Apart from the benefits regarding safety and costs, it also provides an extra handle for the chemist for improving rate and selectivity as different reducing agents, such as secondary alcohols or formate salts can be used. In addition, there is a very wide range of catalysts, homogeneous and heterogeneous, to choose from. This review covers the literature of the past 30 years on metal-catalysed transfer hydrogenation of α,β-unsaturated ketones and aldehydes to unsaturated alcohols using homogeneous or heterogeneous catalysts.

1-Hydroxy-2,5-hexanedione, obtained in good yield from renewable 5-hydroxymethylfurfural, is a versatile building block for a variety of new compounds.

The synthesis of a new tripodal phosphine ligand, N(CH 2 PEt 2 ) 3 , N-TriPhos Et is reported, and the use of tripodal ligands of this type, N(CH 2 PR 2 ) 3 (R = Ph, Et), in conjunction with ruthenium for the catalysed hydrogenation of dimethyl oxalate (DMO) is reported and contrasted with catalysis using the MeC(CH 2 PPh 2 ) 3 (TriPhos Ph ) ligand. A different order of reaction with respect to the DMO substrate is found, and the rate is slower. A study of the kinetics and mechanism of the hydrogenation of DMO with Ru(acac) 3 /TriPhos Ph is described, along with the effect of different additives to the system. The performance of Ru(acac) 3 /TriPhos Ph /Zn system with unactivated ester substrates is probed and found to proceed significantly slower. Finally, based upon experimental observations, a mechanism is proposed for ester hydrogenation using ruthenium catalysts with tripodal phosphine ligands. Key words Ruthenium Phosphine Hydrogenation Ester Tripodal

Diols prepared via solvent-free acetalisation of hydroxymethylfurfural with glycerol were incorporated as additives into polyurethanes based on a bioderived polyether polyol. Moisture-cured as well as acrylate cross-linked films of these PUs were prepared. Both materials displayed excellent thermal stability and could be cleaved in acidic solutions. In particular the highly cross-linked film produced from the acrylate endcapped polyurethanes displayed a clear tuneability of the degradation behaviour according to the amount of acetal additive incorporated. This system has the potential to be used for the selective debonding of polyurethane-based adhesives at the end of their lifetime to facilitate the recycling of expensive components and raw materials from complex devices such as consumer electronics.